acwing131. 直方图中最大的矩形()

#include "bits/stdc++.h"
using namespace std;
 const int N=1e5+3;
 #define int long long
 int n,a[N];
 int hh,stk[N],w[N];
 
 void sov(){
     hh=0;
     memset(a,0,sizeof a);
     stk[n+1]=w[n+1]=0;
     int i,ans=0;
     
     for(i=1;i<=n;i++) cin>>a[i];
     for(i=1;i<=n+1;i++){
         int t=0;
         while(hh>0&&stk[hh]>=a[i]){
             t+=w[hh];
             ans=max(ans,t*stk[hh]);
             hh--; 
         }
         stk[++hh]=a[i]; w[hh]=t+1;
     }
     cout<<ans<<endl;
 }
  main(){
     while(cin>>n,n) sov();
 }
————————
#include "bits/stdc++.h"
using namespace std;
 const int N=1e5+3;
 #define int long long
 int n,a[N];
 int hh,stk[N],w[N];
 
 void sov(){
     hh=0;
     memset(a,0,sizeof a);
     stk[n+1]=w[n+1]=0;
     int i,ans=0;
     
     for(i=1;i<=n;i++) cin>>a[i];
     for(i=1;i<=n+1;i++){
         int t=0;
         while(hh>0&&stk[hh]>=a[i]){
             t+=w[hh];
             ans=max(ans,t*stk[hh]);
             hh--; 
         }
         stk[++hh]=a[i]; w[hh]=t+1;
     }
     cout<<ans<<endl;
 }
  main(){
     while(cin>>n,n) sov();
 }